The present invention relates to methods and apparatus for facilitating the measurement of a vehicle dimension, in particular a vertical distance between a vehicle wheel axis and the underside of a fender lip of the vehicle.
Among the maintenance checks which are routinely performed on vehicles is a procedure to determine the extent to which the coil springs of the suspension system may have sagged. This procedure, which involves measuring a height dimension of the vehicle, can be performed in various ways as devised by the manufacturer of the particular vehicle. Traditionally, the procedure involves taking vertical measurements between the ground and various points on the vehicle body. Those actual measurements are compared with predetermined values set out in a book of specifications published by the manufacturer, in order to determine to what extent the springs may have sagged. The method of locating the various measuring points on the vehicle can be intricate, making the measurements difficult to obtain and prone to error. This discourages the use of the procedure.
There has been proposed a less complex measuring procedure for checking vehicle height. With reference to FIGS. 11 and 12, that procedure involves measuring a vertical height H from the center axis CA of each wheel W to the underside U of the fender lip E associated with the particular wheel. Those measurements are then compared with predetermined values compiled for the make and model of that vehicle.
However, it is difficult to manually make such a measurement in an accurate manner, due to the horizontal distance D existing between the end of the wheel axle CA and the vertical plane of the fender lip F (see FIG. 12). That is, an operator who orients a ruled measuring element such as a stick or tape so that it extends vertically downwardly from the underside U of the fender lip, cannot accurately determine where the centerline CA of the wheel (i.e., the axis of rotation of the axle) intersects the measuring element. It would, therefore, be desirable to enable measurements of that type to be accurately made in a simple manner.